package uk.ac.ox.zoo.seeg.abraid.mp.publicsite.security;

import org.springframework.http.HttpStatus;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * Customise AuthenticationFailureHandler to return error message instead of redirect.
 * The request was successfully handled, but the user login authentication failed.
 * Copyright (c) 2014 University of Oxford
 */
public class AjaxAuthenticationFailureHandler extends SimpleUrlAuthenticationFailureHandler {
    /**
     * Prepares response JSON so AuthenticationException may be passed to and handled by the ajax success callback.
     * @param request The HTTP servlet request
     * @param response The HTTP servlet response
     * @param auth The authentication exception, eg "Bad credentials"
     * @throws IOException if the superclass throws this exception
     * @throws ServletException if the superclass throws this exception
     */
    public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response,
                                        AuthenticationException auth) throws IOException, ServletException {
        response.setStatus(HttpStatus.UNAUTHORIZED.value());
        response.getWriter().print(auth.getMessage());
        response.getWriter().flush();
    }
}